Effects of metoprolol on cardiomyocyte apoptosis and caspase-12 activation after coronary microembolization in rats

AIM: To investigate the effects of metoprolol on cardiomyocyte apoptosis and caspase-12 activation after coronary microembolization in rats. METHODS: 30 rats were randomized to sham-operated group (S group), coronary microembolization group (CME group) and metoprolol group. Coronary microembolization models were produced by injection of 42 μm microspheres (3000/0.1mL) into the left ventricle during 10 seconds ascending aorta occlusion in rats. The S groups were injected saline instead. Intravenous metoprolol was infused into the rats assigned to the metoprolol groups.Cardiomyocyte apoptosis was detected with in TUNEL staining. The activation of caspase-12 was measured by Western blotting analysis. Left ventricular ejection fraction (LVEF) was assessed by transthoracic two-dimensional echocardiography. RESULTS: ① LVEF was significantly decreased in CME group compared to S group (P<0.05). No statistical difference between the metoprolol group and CME group was observed. ②Compared with S group, the apoptosis rate of cardiomyocytes and the levels of activated caspase-12 proteins in CME group were significantly increased (all P<0.05). Compared with CME group, the apoptosis rate of cardiomyocyte and the levels of activated caspase-12 proteins in metoprolol group were significantly decreased (all P<0.05). CONCLUSION: Metoprolol inhibits the apoptosis of cardiomyocytes and the activation of caspase-12 after coronary microembolization.     

Astragalus polysaccharides improve chronic heart failure by promoting myocardial FFA metabolism via AMPK pathway

AIM: To investigate the effect of Astragalus polysaccharides (APS) on chronic heart failure and its mechanism. METHODS: Male SD rats (n=32) were randomly divided into control group, sham group, model group and APS group (8 rats in each group). The left coronary artery ligation in the rats was conducted to establish myocardial infarction heart failure model. After modeling, the rats in APS group were given APS (3 g·kg^-1·d^-1) by intragastric administration for 6 weeks. Left ventricular diastolic diameter (LVD), left ventricular systolic diameter (LVS), left ventricular ejection fraction (LVEF) and fractional shortening (FS) were detected by echocardiography. HE staining was used to observe the pathological changes. The concentrations of free fatty acid (FFA) in the serum and myocardium were observed by the method of acetyl coenzyme A synthetase and acetyl coenzyme A oxidase (ACS-ACOD). The protein levels of total AMP-activated protein kinase (AMPK), phosphorylated AMP-activated protein kinase (p-AMPK), fatty acid translocase (FAT/CD36) and carnitine palmitoyltransferase I (CPT-1) were measured by Western blotting. RESULTS: No significant difference in each index between sham group and control group was observed. Compared with control group, LVEF and FS in model group was significantly decreased, while LVD and LVS was significantly increased (P<0.05). The LVEF and FS in APS group were significantly improved compared with model group (P<0.05), and there was no significant difference between APS group and control group. LVD and LVS in APS group were obviously improved compared with mo-del group (P<0.05), and the difference was significant compared with control group (P<0.05). Compared with control group, focal myocardial necrosis increased, and residual myocardial cells reduced in model group, while those was much better in APS group as compared with model group (P<0.05). The FFA concentrations in the serum and myocardium in model group increased significantly compared with control group (P<0.05), while those decreased significantly in APS group as compared with model group (P<0.05). The protein levels of p-AMPK, CPT-1, and cell membrane FAT/CD36 in model group decreased significantly compared with control group (P<0.05), and those in APS group increased obviously compared with control group (P<0.05). CONCLUSION: APS improves chronic heart failure by activating the AMPK pathway and promoting myocardial ingestion and utiliation of FFA.     

Effect of transplantation of hRAMP1 gene-modified bone marrow MSCs on postangioplasty neointima formation in rabbits

AIM: To explore the effect of transplantation of human receptor activity-modifying protein 1 ( hRAMP1 ) gene-modified bone marrow mesenchymal stem cells (MSCs) on neointima formation after carotid balloon angioplasty in carotid atherosclerosis rabbits. METHODS: MSCs were collected through density gradient centrifugation and adherent culture. MSCs were transfected with adenovirus vector carrying hRAMP1 gene to generate hRAMP1 gene-modified MSCs (hRAMP1-MSCs). All animals with carotid atherosclerosis and balloon angioplasty were randomly divided into hRAMP-MSCs group, MSCs group and control group. After the model was established, MSCs transfected with pAd2-EGFP-hRAMP1 or pAd2-EGFP and PBS were injected to the ear vein,respectively. The injured carotid arteries were harvested to detect the homing of MSCs,reendothelialization and neointima thickness 7 d, 14 d and 28 d after cell transplantation. The plasma samples were collected for detecting vascular endothelial growth factor (VEGF) by ELISA. The expression of endothelial nitric oxide synthase (eNOS) in injured carotid arteries was measured by Western blotting. RESULTS: The expression of CD31 and EGFP was observed in the neointima at different time points in hRAMP1-MSCs group and MSCs group. Compared to control group, the reendothelialization of carotid significantly increased in both hRAMP1-MSCs group and MSCs group at different time points (P<0.05), and that in hRAMP1-MSCs group showed better than that in MSCs group (P<0.05). The area of neointima and the rate of restenosis were lower in hRAMP1-MSCs group and MSCs group than those in control group, and those in hRAMP1-MSCs group were significantly lower than those in MSCs group. The plasma level of VEGF and the expression of eNOS in the injured carotid arteries were significantly higher in both hRAMP1-MSCs group and MSCs group than those in control group at different time points (P<0.05), and those in hRAMP1-MSCs group were better than those in MSCs group (P<0.05). In the injured carotid arteries, the expression level of proliferating cell nuclear antigen (PCNA) in hRAMP1-MSCs group was the lowest,with the middle level in MSCs group and the highest level in control group. CONCLUSION: The hRAMP1 gene-modified MSCs are better in promoting reendothelialization and attenuating neointima than natural MSCs. The recombinant hRAMP1 adenovirus vectors dont affect the differentiation potential of MSCs into endothelial cells.These findings indicate that the modified stem cells have the potency of more effective reendothelialization to decrease restenosis after angioplasty.     

Inhibitory effects of right cervical sympathetic trunk transection on inflammatory response after acute myocardial infarction in rats and its influence on HMGB1/TLR4/NF-κB signaling pathway

AIM: To observe the effects of transection of right cervical sympathetic trunk (TCST) on inflammatory response and expression of high mobility group box 1 (HMGB1) and TLR4/NF-κB signaling pathway in the rats after acute myocardial infarction (AMI). METHODS: AMI model was established by ligation of left anterior descending coronary artery in SD rats, then the model rats were randomly divided into MI group and MI+TCST group. MI+TCST model was performed by transection of right cervical sympathetic trunk after left anterior descending coronary artery ligation. The rats in MI group and MI+TCST group were divided into 1, 3, 7, 14 and 28 d subgroups, and another sham operation group threading without ligation, with 8 rats in above each group. After modeling for 4 weeks, the cardiac function was measured by echocardiography. All rats were killed to harvest the hearts for mesuring cardiac hypertrophy index. The myocardial tissue close to infarction was observed with HE staining. The relative mRNA expression levels of HMGB1, tumor necrosis factor α(TNF-α) and interleukin (IL)-6 at different time points were detected by real-time PCR. The protein expression of HMGB1 and TLR4 at different time points after AMI was determined by Western blot. The effect of transection of right cervical sympathetic trunk on the expressions of HMGB1 and TLR4/NF-κB signaling pathway was also analyzed.RESULTS: Compared with the MI group, left ventricular ejection fraction (LVEF) and left ventricular shorterning fraction (LVFS) were significantly higher (P<0.05), left ventricular end-diastole dimension (LVEDd), left ventricular end-systole dimension (LVESd) and cardiac hypertrophy index were significantly lower (P<0.05), and the mRNA levels of HMGB1, TNF-α and IL-6 decreased significantly in MI+TCST group (P<0.05). Western blot results revealed that the protein expression level of HMGB1 increased in the infarct border zone at 3 d, and reached its peak at 7 d, then gradually decreased, and at 28 d after MI in MI group was still significantly higher than that in sham group (P<0.05). The protein expression of TLR4 was consistent with that of HMGB1. Transection of right cervical sympathetic trunk reduced protein expression of HMGB1 and TLR4/NF-κB signaling pathway-related proteins (P<0.05).CONCLUSION: Transection of right cervical sympathetic trunk improves ventricular remodeling and maintaining cardiac function. The mechanism may be related to inhibiting HMGB1/TLR4/NF-κB signaling pathway to reduce inflammatory response.     

Effect of angelica on myocardial fibrosis post myocardial infarction in rats

AIM: To investigate 1) the role of transforming growth factor-β₁ (TGF-β₁) and macrophage infiltration during the development of myocardial fibrosis (MF) in rats after myocardial infarction (MI);and 2) mechanisms of MF post-MI and the inhibitory effect of angelica.METHODS: Sprague-Dawley (SD) rats were subjected to MI by ligating the left anterior descending coronary artery.The animals were randomly divided into three groups: sham, MI and MI+angelica.After 24 hours of ligation, rats received angelica (20 mL·kg^-1·d^-1, ip) or saline.Left ventricular hemodynamics were measured and rats were killed at week 1, week 2 and week 4, respectively.Collagen content, macrophage infiltration and TGF-β₁ expression were examined in the non-infarcted area.RESULTS: ① In MI group, the numbers of macrophage and TGF-β₁ expression were significantly upregulated compared to sham at week 1 post-MI and remained elevated at week 4 (P<0.01).Angelica significantly decreased macrophage infiltration and TGF-β₁ expression (P<0.01 vs MI).② Collagen content was increased significantly in MI group compared to sham at week 2 and week 4 (P<0.01), and decreased in MI+angelica group (P<0.05 vs MI).③ Cardiac function was markedly decreased post-MI in MI group (P<0.01), and improved at week 4 in MI+angelica group (P<0.05).CONCLUSION: In MF post-MI, angelica may have an antifibrotic effect by decreasing macrophage infiltration and TGF-β₁ expression, by which reactive myocardial fibrosis is reduced, and cardiac function is improved.     

Effects of transplantation of peripheral blood mesenchymal stem cells with hypoxia preconditioning on postangioplasty restenosis in rabbits

AIM: To investigate the function and the mechanism of transplanting bone marrow derived peripheral blood mesenchymal stem cells (PBMSCs) on restenosis after carotid balloon angioplasty in the model of carotid atherosclerosis rabbits, and to determine if the functions of PBMSCs are enhanced after hypoxia preconditioning. METHODS: Bone marrow cells were mobilized by granulocyte colony-stimulating factor (G-CSF), and PBMSCs were collected through density gradient centrifugation and adherent culture, labeled with enhancement type green fluorescent protein (EGFP) genes. All animals with carotid atherosclerosis stenosis were randomly divided into three groups: hypoxia preconditioning group (n=24, received intravenous transplantation of PBMSCs with hypoxia preconditioning), non-hypoxia preconditioning group (n=24, received normal culture of PBMSCs) and control group (n=24, only received equal-volume of culture medium). Vascular endothelial growth factor (VEGF) was determined by enzyme linked immunosorbent assay (ELISA) at 7 d, 14 d and 28 d post-angioplasty, respectively. The vessel morphology, the homing of MSCs and the reendothelialization were analyzed with Weigert staining and immunohistochemistry. RESULTS: Compared to control group, the level of VEGF significantly increased in both hypoxia preconditioning group and non-hypoxia preconditioning group at all time points (P<0.01). The level of VEGF in hypoxia preconditioning group was higher than that in non-hypoxia preconditioning group (P<0.05) at 7 d and 14 d, but no difference at 28 d post-angioplasty was observed. At 7 d, GFP-positive cells were found both in hypoxia preconditioning group and non-hypoxia preconditioning group. Neointima thickening and the rate of restenosis were lower in hypoxia preconditioning group than those in non-hypoxia preconditioning group at 28 d (P<0.05), but both hypoxia preconditioning group and non-hypoxia preconditioning group were markedly lower than that in control group (P<0.01). The reendothelialization in hypoxia preconditioning group was outweigh than that in non-hypoxia preconditioning group (P<0.05), but both two groups were lower than that in control group (P<0.01). CONCLUSION: Intravenous transplantation of PBMSCs contributes to the reendothelialization, and attenuates neointima thickening after carotid balloon-induced injury in the rabbit model. Further, hypoxia preconditioning may strengthen the above function of MSCs, which is corelated with the increase in cytokines induced by hypoxia preconditioning to MSCs.     

Effect of livin-modified BM-MSCs transplantation on cardiac function following acute myocardial infarction in a rat model

AIM: To study the effect of livin gene-modified bone marrow mesenchymal stem cells(BM-MSCs) transplantation on the cardiac function following acute myocardial infarction in a rat model and the expression of livin, caspase-3, caspase-7 and caspase-9 in the livin gene-modified BM-MSCs. METHODS: The MSCs were obtained by the whole bone marrow culture method, and the apoptosis of the MSCs after infection with adenovirus vector carrying enhanced green fluorescent protein(EGFP) gene and livin recombinant vector(rAd-livin) were detected by flow cytometry. The expression of livin, caspase-3, caspase-7 and caspase-9 was detected by Western blot. After permanent left anterior descending artery occlusion, the rats were randomized to receive intramyocardial injection of DMEM without cells(vehicle group), or containing MSCs(MSCs group), MSCs(EGFP)(rAd-control/MSCs group) or MSCs(livin)(rAd-livin/MSCs group). Left ventricular systolic pressure(LVSP), left ventricular end-diastolic pressure(LVEDP), the maximum increased rate of left ventricular pressure(-dp/dt_max) and the maximum decline rate of left ventricular pressure(+dp/dt_max) were recorded for evaluating the cardiac functions. RESULTS: The apoptosis of rAd-livin/MSCs was significantly decreased as compared with MSCs and rAd-control/MSCs(P<0.05). Meanwhile, the expression of caspase-3, caspase-7 and caspase-9 was significantly downregulated as compared with the other 2 groups(P<0.05). The cardiac function in rAd-livin/MSCs group was significantly improved as compared with DMEM group, and those in the other 2 groups got the similar results, but the function in rAd-livin/MSCs group was better improved. Meanwhile, the number of surviving cells in rAd-livin/MSCs group was significantly improved as compared with the other 2 groups. CONCLUSION: The apoptosis of MSCs is decreased after rAd-livin transfection, and the expression of caspase-3, caspase-7 and caspase-9 is also significantly downregulated while the expression of livin is significantly upregulated. Transplantation of livin-modified BM-MSCs by lentiviral vector results in better prognosis for treating myocardial infarction by enhancing cell survival.     

Effect of mesenchymal stem cells infusion on hematopoietic recostitution after peripheral blood stem cell transplantation in mice

AIM: To study the effect of mesenchymal stem cells (MSCs) infusion on hematopoietic recovery after peripheral blood stem cell transplantation in mice. METHODS: BALB/c mice conditioned by high dose chemotherapy/radiotherapy were infused with10⁶ peripheral blood mononuclear cells (PBMC) mobilized by granulocyte colony-stimulating factor (PBSCT group),10⁴ MSCs culture-expanded in vitro and10⁶ PBMC(experimental group1),10⁶ MSCs and10⁶ PBMC(experimental gruop 2). Survival rate within 4 weeks, white blood cell count, bone marrow nucleated cells (BMNC), granulocyte-macrophage colony forming unit(GM-CFU) and fibroblast colony forming unit (F-CFU) were examined. RESULTS: Survival rate, BMNC, GM-CFU, F-CFU were significantly higher in experimental group 2 than that in PBSCT group (P<0.05), WBC recovery was faster (P<0.01) and F-CFU level was higher in experimental group1than that in PBSCT group (P<0.05). CONCLUSION: Mesenchymal stem cells infusion enhanced hematopoietic reconstitution after peripheral blood stem cell transplantation.     

Effect of human β-NGF gene-modified bone marrow-derived mesenchymal stem cells on rotational behavior of rats with Parkinson disease

AIM：To investigate the effect of human β-nerve growth factor (β-NGF) gene-modified bone marrow-derived mesenchymal stem cells (MSCs) transplantation on the rotational behavior improvement in a rat model of Parkinson disease (PD). METHODS：The rat model of PD was established successfully and the animals were divided into 4 groups:β-NGF-MSCs group (transplanted with 5×105 β-NGF-engineered MSCs), MSCs group (transplanted with 5×105 MSCs), DMEM/F12 group (5 μL transplantation medium was injected in the right striatum of the rats) and PD model group (without transplantation). The rotational scores were assessed 2 weeks, 4 weeks and 6 weeks after transplantation. At different time points after transplantation, the rats were tested for apomorphine (APO)-induced rotational behavior and the brains of the PD model rats were examined by fluorescence microscopy and immunohistochemical staining. RESULTS：Transplantation of human β-NGF gene-modified MSCs effectively improved the behavioral performance in the rats. At the 2nd, 4th and 6th weeks after cell transplantation, the rotational frequencies after injection of APO decreased significantly in β-NGF-MSCs group compared with MSCs group and PD group (P<0.05). Both β-NGF gene-modified MSCs and MSCs survived in the brains of PD model rats, had good compatibility with the host cells, and showed no signs of destroying the host and the glial cicatrisation. The β-NGF gene-modified MSCs expressed β-NGF stablely in the brains of PD model rats, and showed obvious improvement of the rotational behavior in the PD model rats induced by APO compared with MSCs group. CONCLUSION:The behavior of the rats with PD is significantly improved by transplanting β-NGF-modified MSCs in right striatum, and β-NGF gene therapy has potential clinical value．     

Differentiation of bone marrow mesenchymal stem cells into cardiomyocyte-like cells in vitro via cardiotrophin 1

AIM: To investigate the effects of cardiotrophin 1 (CT-1) on differentiation of swine bone marrow mesenchymal stem cells (MSCs) into cardiomyocyte-like cells in vitro.METHODS: MSCs were isolated and proliferated from Tibet miniswine. Adipogenic and osteogenic potentials were identified. MSCs were divided into 4 groups for induction: untreated group, 5-azacytidine (5-Aza) group,CT-1 group and 5-Aza combined with CT-1 group. After induction for 4 weeks, the expression of cardiac cell markers including α-actin and cardiac troponin-T (cTnT) was estimated by immunofluorescence staining. Finally, the rates of red fluorescence positive-staining cells were calculated. RESULTS: The expression of α-actin in the 4 groups by red fluorescence staining was as follows: the differentiation rate of cardiomyocyte-like cells in combination group was 29.90%±4.76%, significantly higher than that in 5-Aza group (17.73%±2.34%, P<0.01), CT-1 group (6.63%±0.55%, P<0.01) and untreated group (1.62%±0.09%, P<0.01). The differentiation rate in 5-Aza group was significantly higher than that in CT-1 group (P<0.01) and untreated group (P<0.05). The differentiation rate in CT-1 group was significantly higher than that in untreated group (P<0.01). The expression of cTnT in the 4 groups was as follows: the differentiation rate of cardiomyocyte-like cells in combination group was 36.50%±4.09%, significantly higher than that in 5-Aza group (14.37%±1.65%, P<0.01), CT-1 group (7.50%±0.61%, P<0.01) and untreated group (1.12%±0.23%, P<0.01). The differentiation rate in 5-Aza group was significantly higher than that in CT-1 group (P<0.01) and untreated group (P<0.01). The differentiation rate in CT-1 group was significantly higher than that in untreated group (P<0.01).CONCLUSION: Appropriate concentrations of 5-Aza (10 μmol/L) and CT-1 (0.1 μg/L) induce swine bone marrow MSCs to differentiate into cardiomyocyte-like cells in vitro. CT-1 combined with 5-Aza significantly increases the differentiation rate.     

Long-term insulin treatment improves postischemic cardiac structure and function via increasing serum BNP levels

AIM：To investigate the influence of long-term insulin treatment on postischemic cardiac structural and functional changes, and to further explore the underlying mechanisms. METHODS：Adult male SD rats were randomly divided into 4 groups (8~10 rats per group): sham group, myocardial infarction (MI) + saline (1 mL·kg-1·d-1, hypodermic injection for 4 weeks) group, MI + insulin (2 U·kg-1·d-1, hypodermic injection for 4 weeks) group and MI + insulin (2 U·kg-1·d-1, hypodermic injection for 4 weeks) + wortmannin ［a phosphatidylinositol 3-kinase (PI3K) inhibitor; 15 μg·kg-1·d-1, intraperitoneal injection 15 min before each insulin treatment］ group. The rats in the latter 3 groups were subject to ligation of the left anterior descending coronary artery, while those in sham group underwent the same surgical procedures without tying the sutures. The cardiac structural and functional changes were observed by echocardiogram, heart catheterization and microscopy with HE and Masson trichrome staining. Blood glucose was determined by Roche blood glucose meter, and the serum levels of insulin and brain natriuretic peptide (BNP) were detected by ELISA. The protein expression and phosphorylation of PI3K, Akt, glycogen synthase kinase 3β (GSK3β) and p38 mitogen-activated protein kinase (p38 MAPK) in myocardial tissues were detected by Western blotting. The mRNA expression of BNP, β-myosin heavy chain (β-MHC) and atrial natriuretic peptide (ANP) in myocardial tissues was determined by real-time fluorescence quantitative PCR. RESULTS：At the end of the 4th week, MI rats receiving long-term insulin treatment showed decreased ratio of heart length/heart weight, smaller systolic left ventricle cavity, thicker systolic interventricular septum, and increased cardiac ejection fraction, left ventricular development pressure and instantaneous first derivate of left ventricle pressure (P<0.05 vs MI + saline group). Moreover, insulin treatment significantly increased the phosphorylation of PI3K and Akt and the serum level of BNP, and inhibited the phosphorylation of p38 MAPK (P<0.05 vs MI + saline group), but did not change the mRNA expression of BNP in myocardial tissues. The effects of insulin on BNP were not blocked by wortmannin (P>0.05 vs MI + insulin group). CONCLUSION：Insulin improves postischemic cardiac structure and function by increasing serum BNP levels possibly independent of PI3K-Akt signaling pathway.     

Inhibitory effect of aerobic exercise on left ventricular remodeling and sympathetic neural remodeling in rats with heart failure after myocardial infarction

AIM: To investigate the effects of long-term aerobic exercise on the heart and sympathetic neural remodeling (structure and function remodeling) in heart failure rats induced by myocardial infarction. METHODS: Heart failure model after myocardial infarction was performed by ligating anterior descending coronary artery in the Wistar rats. Four weeks after operation, the rats were randomly divided into sham operation sedentary (S) group, heart failure sedentary (H) group and heart failure exercise (HE) group. The animals in HE group underwent 10-week treadmill running, while those in S group and H group were sustained in a resting state. The cardiac structure and function including left ventricular internal diameter at diastole (LVIDd), left ventricular internal diameter at systole (LVIDs), left ventricular anterior wall diameter at diastole (LVAWDd), left ventricular anterior wall diameter at systole (LVAWDs), left ventricular posterior wall diameter at diastole (LVPWDd) and left ventricular posterior wall diameter at systole (LVPWDs), and cardiac function parameters including fractional shortening (FS) and left ventricular ejection fraction (LVEF) were measured by echocardiography. The myocardium was collected for histopathological observation with Masson staining, and the collagen volume fraction (CVF) was determined. The concentrations of norepinephrine (NE) in the myocardium and plasma were measured by high-pressure liquid chromatography. The frequency domain analysis was applied for determining the heart rate variability (HRV) via subcutaneous recording electrode involving total power (TP), normalized low power (LFn), normalized high power (HFn) and LF/HF ratio. The mRNA expression of collagen type I (Col-I), collagen type III (Col-III), atrial natriuretic factor (ANF), α-myosin heavy chain (α-MHC), β-myosin heavy chain (β-MHC), sarcoplasmic endoplasmic reticulum Ca²⁺-ATPase (SERCA2a) was detected by real-time PCR. The protein levels of nerve growth factor (NGF) and its receptor (TrkA), and tyrosine hydroxylase (TH) were measured by Western blotting. RESULTS: (1) Compared with S group, body weight (BW), LVIDd, FS, LVEF, TP, HFn, the mRNA expression of α-MHC and SERCA2a, and the protein levels of NGF, TrkA and TH decreased (P<0.05). Left ventricular weight (LVW), left ventricular mass index (LVMI), LVAWDd, LVAWDs, LVPWDd, LVPWDs, CVF, plasma and myocardial NE content, LFn, LF/HF, and the mRNA expression of ANF, β-MHC, Col-I and Col-III increased (P<0.05) in H group. (2) Compared with H group, LVW, LVMI, LVIDd, FS, LVEF, TP, HFn, the mRNA expression of α-MHC and SERCA2a, and the protein levels of NGF, TrkA and TH were raised (P<0.05), while CVF, plasma and myocardial NE content, LFn, LF/HF, and the mRNA expression of ANF, β-MHC, Col-I and Col-III decreased (P<0.05) in HE group. CONCLUSION: Long-term aerobic exercise training leads to inhibition of heart and sympathetic neural remodeling and improvement of cardiac function and autonomic modulation in the rats after myocardial infarction.     

Therapeutic efficacy of Ang-1 gene-modified MSCs in cerebral infarction

AIM: To observe the therapeutic efficacy of Ang-1 gene-modified mesenchymal stem cells (MSCs) in cerebral infarction. METHODS: The constructed lentiviral vector carrying the Ang-1 gene was used to infect the rat mesenchymal stem cells (rMSCs) to establish the Ang-1 gene-modified rMSCs (Ang-rMSCs). Adult male F344 rats were subjected to transient (2 h) middle cerebral artery occlusion (MCAO) with modified Zea Longa method. Phosphate buffered saline (PBS, 1 mL 0.1 mol/L, for control group), or Ang-rMSCs suspension (1 mL, for Ang-rMSCs group), or rMSCs suspension (1 mL, for pNL-rMSCs group), were infused into tail vein of rat respectively at 24 h after MCAO (n=8 in each group). Functional recovery measurements using the modified neurological severity scores (mNSS) were performed at 24 h post-MCAO and 1 week, 1 month and 3 months post-transplantation, respectively. The quantitative evaluation of blood-brain barrier permeability was performed at 1 week post-transplantation. The distribution, differentiation and malignant sign of grafted rMSCs were observed with immunofluorescence staining and histological method. RESULTS: Significant neurological function improvement was observed in groups treated with Ang-rMSCs or pNL-rMSCs at 1 week, 1 month post-transplantation compared with that in control group, as evidenced by mNSS (P<0.01). Better neurological function improvement was also found in Ang-rMSCs group than that in pNL-rMSCs group (P<0.01). The results of quantitative evaluation of blood-brain barrier permeability showed that the permeability in Ang-rMSCs group was the lowest compared to those in other two groups (P<0.01), and in the pNL-rMSCs group was the lower than that in control group (P<0.01). The grafted rMSCs survived in Ang-rMSCs and pNL-rMSCs groups, most were localized around the ischemic focus, and a few of them expressed NSE, NF and GFAP. The grafted rMSCs expressed BDNF abundantly in Ang-rMSCs group. These grafted rMSCs survived up to 3 months at least. No malignant sign was observed in these grafted cells. CONCLUSION: Ang-1 gene-modified MSCs transplantation has better therapeutic efficacy in cerebral infarction than that of MSC transplantation. The transplantation of cells with gene engineering is an effective therapeutic method for stroke patients.     

Effect of Fufang Zhenzhu Tiaozhi capsule on serum lipids and inflammatory factors in rabbit abdominal aortic restenosis model

AIM: To investigate the effect of Fufang Zhenzhu Tiaozhi capsule (FTZ) on serum lipids and inflammatory factors in rabbits with abdorminal aortic restenosis after balloon angioplasty.METHODS: New Zealand white rabbits (n=30) were divided into 5 groups. Except blank control group, the rabbits in other groups were used to establish abdominal aortic endothelium exfoliative vascular stenosis model. After 4 weeks of high-fat diet feeding, the animals in restenosis model group and drug treatment groups underwent percutaneous balloon dilatation in the stenosis. The angiographic stenosis was analyzed by a two-dimensional quantitative coronary angiography workstation with a digital subtraction X-ray machine. Blood samples were taken during angiography and the profiles of serum lipids and cytokines were measured. The expression of nuclear factor-κB (NF-κB) in the blood vessels was determined by immunohistochemistry.RESULTS: Angiography confirmed that the rates of area stenosis and diameter stenosis were significantly decreased in treatment groups compared with restenosis model group (P<0.01). Compared with restenosis model group, the serum lipid profiles and cytokine concentrations in drug treatment groups were significantly decreased (P<0.05). Immunohistochemistry showed the expression of NF-κB in restenosis model group was significantly higher than that in blank control group and drug treatment groups (P<0.05).CONCLUSION: FTZ significantly reduces the blood lipids and inflammatory factors in abdominal aortic restenosis model, and the anti-inflammatory effect may be related to the regulation of NF-κB pathway to inhibit the production of various inflammatory factors.     

Effect of external counterpulsation on asymmetry diethylarginine and endothelin levels in blood

AIM:To observe changes of serum asymmetry dimethylarginine (ADMA) and endothelin-1 (ET-1) levels,which reflect blood vessel endothelial function,after therapy of enhanced external counterpulsation(EECP) in patients who had taken percutaneous transluminal coronary angioplasty and stent.METHODS:Fifty one coronary heart disease patients (all of them had taken percutaneous tranluminal coronary angioplasty and stent) were distributed into two groups by matching them with ratio of 1∶2,17 patients in EECP group and 34 patients in control group.Both of two groups were given conventional medicine,in addition,EECP group was undertaken three courses of treatment of EECP.ADMA was detected by HPLC-fluorescence method,and ET-1 was detected by radio-immunity method.RESULTS:In EECP group ，compared with prior treatment,ADMA and ET-1 levels was obviously reduced (P<0.05).In control group,compared with prior treatment,ADMA had no significant difference (P>0.05) and ET-1 was higher (P<0.01).Compared between two groups,extent of decrease in ADMA and ET-1 levels in EECP group were more obvious than control group (P<0.01).Improvement of angina and decrease of frequency of angina was more obvious in EECP group than control group.Besides,decrease of ADMA level was positive correlation with them (r=0.85，0.70,respectively P<0.01).CONCLUSION:EECP reduces serum ADMA and ET-1 levels by increasing shear stress to vessel endothelium in coronary heart disease patients who had taken percutaneous tranluminal coronary angioplasty.It hints that EECP can improve endothelial function and provides experimental evidence for the combined treatment of coronary heart disease.     

Effect of Shenshuguanxin granula on coronary circulation in rats with myocardial infarction

AIM：To explore the effect of traditional Chinese medicine Shenshuguanxin granula on coronary circulation in a rat model of myocardial infarction (MI). METHODS：SD rats (n=50, SPF grade) were randomly divided into 5 groups (n=10):sham group, MI group, and high-dose, middle-dose and low-dose Shenshuguanxin granula treatment groups. The rat MI model was established by ligation of the coronary artery. The cardiac markers, small and medium-sized blood vessels ［microvessel count (MVC) value］ in the infarct zone, and platelet endothelial cell adhesion mo-lecule 1 (PECAM-1) and vascular endothelial growth factor (VEGF) expression in the infarct border zone were measured. RESULTS：After 4 weeks of coronary artery ligation, the significant increases in MVC in the infarct zone, and the expression of PECAM-1 and VEGF in the infarct border zone were detected compared with sham group (P<0.05). The differences of cardiac markers between MI group and other groups were insignificant (P>0.05). CONCLUSION:Shenshuguanxin granula improves coronary circulation in the rats with myocardial infarction by increasing the expression of PECAM-1 and VEGF, and promoting small and medium-sized angiogenesis.     

Effect of PPARδ activation on expression of MMP-9 and fibronectin in infarcted myocardium

AIM:To investigate the effect of peroxisome proliferator-activated receptor δ (PPARδ) activation with dietary GW610742X on the expression of matrix metalloproteinase-9 (MMP-9) and fibronectin (FN) in infarcted and remodeling myocardium. METHODS: Wistar rats were divided into 4 groups: control group, sham group, myocardial infarction (MI) group and MI+GW610742X (GW) group. The left coronary artery was ligated to establish the MI model. PPARδ activator GW610742X (100 mg·kg^-1·d^-1) was given to the rats in GW group. At the 3rd month of the procedure, the expression of PPARδ, MMP-9 and FN at mRNA and protein levels in the left ventricular free wall(LVFW) of the heart from each group was identified and the distribution of FN was detected by immunofluorescence. RESULTS: After 3 months following the procedure, obvious necrosis and fibrosis in LVFW were observed in MI group. The expression of PPARδ in MI group was higher than that in control, sham and GW groups (P<0.01), and PPARδ expression in GW group was lower than that in control and sham group (P<0.05). In MI and GW groups, the expression of MMP-9 was higher while the expression of FN was lower than those in control and sham group (P<0.05 or P<0.01). In GW group, the expression of MMP-9 was lower (P<0.05) while the expression of FN was higher (P<0.01) than those in MI group. Meanwhile, the expression of MMP-9 and FN in sham group was similar to those in control group (P>0.05). CONCLUSION: MMP-9 is upregulated and FN is downregulated in infarcted myocardium during the remodeling process. Activation of PPARδ inhibits the upregulation of MMP-9 and degradation of FN, thus ameliorating the myocardial remodeling.     

Mitral annulus velocities and time intervals for evaluation of global left ventricular diastolic function in patients with coronary artery disease

AIM: To detect and compare the longitudinal mitral annulus diastolic velocity and time interval changes by pulsed Doppler tissue imaging (DTI) in patients with angina pectoris (AP) and myocardial infarction (MI), and to explore the value of mitral annulus diastolic velocities and time intervals for evaluation of global left ventricular diastolic dysfunction. METHODS: Fifty patients with established coronary artery disease were divided into AP group (16 cases) and MI group (34 cases). Sixteen age-matched healthy individuals served as the control group. The septum, lateral, anterior and inferior walls of the mitral annulus were displayed, and selected for DTI spectrum sampling. Peak early and late diastolic velocities and their ratio, time to the onset and peak of the early diastolic wave, and regional isovolumic relaxation time were measured, and the average values of the four mitral annular sites were calculated and presented as Em, Am, Em/Am, QEm, TEm and IVRTm, respectively. RESULTS: Compared with the control group, Em and Em/Am were significantly lower in both the AP and the MI groups (P<0.01). Em was even lower in the MI group than that in the AP group (P<0.01). QEm, TEm and IVRTm were significantly longer in the AP and the MI groups than those in control group (P<0.01 or P<0.05). IVRTm was even longer in the MI group than that in AP group (P<0.01). IVRTm had significantly negative correlation with Em (r=-0.64, P<0.01). CONCLUSION: Em, Em/Am, QEm, TEm and IVRTm as measured by pulsed DTI may be promising indexes for quantitative assessment of global left ventricular diastolic dysfunction in patients with coronary artery disease. Em and IVRTm may indicate the severity of ischemic myocardial damage.     

Protective effects of basic fibroblast growth factor (bFGF) against to myocardial ischemia in rats

AIM: To study the protective effects of basic fibroblast growth factor (bFGF) on myocardial ischemia in rats and their underlying mechanism. METHODS: A rat myocardial ischemic injury model was established by left coronary artery ligation. The rats were killed at 2 h, 4 h, 8 h after coronary artery occlusion. The samples of blood and myocardium were collected for observing the expression of Bcl-2 and Bax in myocardial cells and the changes of superoxide dismutase (SOD) or myocardial enzymes. RESULTS: The amount of Bcl-2 protein expression of myocardial cells in ischemia + bFGF group was significantly higher than that in ischemia+saline group (P＜0.01) at 2 h, 4 h after coronary artery occlusion. However, the change of Bax protein expression was reversed (P＜0.05). The activity of SOD in ischemia+bFGF group was higher than that in ischemia+saline group, and the changes of LDH, CK-MB and α-HBDH in ischemia+bFGF group were reversed (P＜0.05) in serum. CONCLUSION: bFGF has protective roles against myocardial ischemia in rats.